Blowhole plug for sand boxes or containers



July 1, 1947.

A. H. PETERSON BLOWHOLE PLUG FOR SAND BOXES OR CONTAINERS Filed Oct. 3,1945 IEEE.

INVENTOR. flH. Pelemozz V ATTORNEY Patented July 1, 1947 umrso BLOWHOLEPLUG FOR SAND BOXES on CONTAINERS Axel H. Peterson, Rock Island, 111.Application October 3, 1945 Serial No. 620,060

My present invention relates to molding apparatus and more particularlyto improvements in sand boxes or containers for molding sand.Specifically, my invention relates to means for preventing the escape ofsand and air between the sand box and, for example, a core box, whensand is being blown from the sand box to the core box. It is a commonexperience in molding to find that the, metal parts do notfit togetherclosely enough to prevent air from blowing through between the bottom ofthe sand box and the top of the core box, said air carrying with it finesand which scores the adjacent metal parts, thus causing an increase inleakage of air. I have found that, by enlarging the blow hole in thebottom or base plate of the sand box, tapping the same, and puttingthrough this hole a screw-threaded plug formed from a substance such asneoprene or a combination of neoprene andmetal, with the syntheticextending slightly below the bottom of the bottom plate, a suflicientlytight engagement can be made around the blow hole to prevent air fromescaping between the plug and the core box, thus eliminating thisblow-by.

In the drawings annexed hereto and forming a part hereof, f

Fig. 1 represents, fragmentarily, a vertical, longitudinal section of acore-forming machine embodying my present invention;

Figs. 2 and 3 represent, respectively, a plan view and a longitudinalsection of one type of plug which I have produced for the purposestated;

Figs. 4 and 5 represent, respectively, a plan view and a longitudinalsection of another form of this plug; and

Figs. 6 and '7 represent, respectively, a plan view and a longitudinalsection of still another form of this plug.

Reference will now be made in greater detail to the annexed drawings fora more complete description of this invention. The sand box is shown atI and it will be understood that this is merely typical of many forms ofsand boxes now well known in the art. At 2 is shown the bottom platewhich is secured to the sand box by bolts 3, in a manner comparable tothat disclosed in the Demmler Patent No. 1,480,747. By enlarging theblow hole in the plate 2 and tapping this, as shown at 4, it is possibleto screw into this opening a screw-threaded plug 5a, 5b, 50 or a similarplug of some other form. I have chosen to illustrate a core box 6 ascomprising upper and lower parts 6a and 6b which are detachablyconnected by the dowel pins I. This core box is shown as resting on aplatform 8 which may be raised to press 1 Claim. (Cl. 22-16) the uppersurface 9 against the lower edge of the plug, with the holes I'll and Hin registry. It is not necessary to have the plug extending much belowthe plate 2 as it is only necessary to have a tight fit between thesurface 9 and the lower end of the plug so as to prevent air blowing outbetween them. i r

I have shown the plug in Figs. 3, 5, and '7' in three diiferent forms,the first two being composite plugs while the last is constructedentirely of a suitable synthetic composition, preferably neoprene. Eachof these plugs is shown as having the upper end of the hole I I enlargedand-formed as a hexagon, in cross-section. This is in'order that a toolof proper form may be inserted in the opening and turned for the purposeof screwing the plug into or out of the hole 4.

The plug of. Figs. Z'and 3 is shown as having an upper metallic sectionM with a lower reduced portion '13 to which is bonded a section Idofvneoprene which continues the general form of section I2, the threads ofthe two sections being identical in shape and continuous so that it ispossible to screw this plug into the base plate 2, as shown in Fig. 1.This plug should extend somewhat beyond the lower face of the plate 2and, preferably, should not extend above the top thereof. Therefore,when the core box 6 is pressed upwardly against the plug, the neopreneyields sufiiciently to form a tight seal entirely around the aperturesI0, II. This will keep air from blowing out between the core box and theplug and will reduce to a minimum the amount of scoring of the face 9and any abutting parts. As shown clearly at I5, the upper end of thehole I I is somewhat enlarged and is hexagonal in form,

thus making it possible to insert a suitable wrench for the turning ofthe plug.

The plug of Figs. 4 and 5 differs somewhat from that of Figs. 2 and 3 inthat the body of the plug is substantially entirely of neoprene withjust a liner extending substantially from end to end of the plug. Theupper end of the enlargement of the hole II is, preferably, flaredsomewhat in order to mak it easier to insert the wrench, as well as toreduce the friction between the plug and the sand entering the hole II.

The plug of Figs. 6 and '7 is made entirely of a yielding, non-metallic,synthetic material, for example, neoprene, and is shown as having thesame external configuration as the other two. This, as well as the othertwo plugs shown, will yield when the core box is pressed against it,thus causing a tight fit and preventing any blowby of the air.

While I have shown three forms of embodiment of the present invention, Ihave embodied this idea in several other forms and the presentdisclosure is therefore to be regarded merely as illustrative, ratherthan showing the entire scope of this invention; however, I prefer thetype of plugs shown in the present drawings.

While I prefer plugs of generally cylindrical configuration withscrew-threaded exterior surfaces fitting in holes of the same generalform in the plate 2 and provided with cooperating screw threads, it willbe understood that various other embodiments of this idea are possible.For example, plugs of generally spool-shaped configuration provided attheir ends with outwardly extending flanges may replace those shown inFigs. 2 to 7, inclusive. The hole in the plate 2 would have its endscountersunk for the reception of the flanges of the plug in order thatthe plug would be held in plac against longitudinal pressure, either upor down. Of course the lower end of this plug would need to projectslightly beyond the bottom of the plate 2. Another form of plug would beone having its middle portion of greater diameter than its two ends, thehole in the plate being under-cut to accommodate the shape of the plug.Another form would be the reverse of that just described, in which themiddle part is small in diameter while the two ends are enlarged. Insuch a case, the plate 2 would need to have the hole 4 reamed out uponopposite sides so that the conical surfaces of the plug would fit thefaces of the metal.

The base plates can be formed with holes of different shapes therein andcan have the plugs molded in these holes and vulcanized in place, withthe lower end projecting slightly beyond the face of the base plate.This would avoid the necessity of enlarging and tapping the hole 4 forthe insertion of threaded plugs, if one wishes to be: spared thenecessity of this extra work. However, I prefer the use ofscrew-threaded plugs as set forth herein.

A simple way of accomplishing the desired end is to provide a base platewith a hole therethrough, as described above, and then counterbore theunderside of this plateso that the hole through the plate has anenlargement at its lower end. A suitable washer, slightly larger indiameter than the counterbore and made of a suitable yielding syntheticmaterial, may then be inserted in the counterbore, with its lowerportion projecting slightly beyond the face of the plate. Then, when thecore box i pressed against this, the space between the sand box and thecore box will be adequately sealed'against blow-by.

It will of course be understood that the specific description ofstructure set forth above may be departed from without departing fromthe spirit of my invention as set forth in this specification and theappended claim.

Havin now described my invention, I claim:

In a maclr'ne of the character stated, a sandfeeding box provided with abottom plate having a screw-threaded sand delivery opening, and a liner,yieldable at its lower end and externally screw-threaded throughout itslength, screwed into said opening and projecting slightly beyond thebottom surface of the plate, said liner having in its upper end anon-circular opening for the reception of a wrench whereby the liner maybe screwed into and removed from the opening in the plate, and saidnon-circular opening having an extension reaching to the lower face ofthe liner and serving to deliver sand to a core box or other place ofuse.

AXEL H. PETERSON.

REFERENCES CITED The following references are of record in the file "ofthis patent:

UNITED STATES PATENTS Germany Mar. 30, 1937

